Synthesis and Chemical Characterization of the Hexanuclear Anions [IR6(CO)14X]- (X=CL, BR, I, OR SCN): Crystal and Molecular-Structures of [PPH4][IR6(MU-CO)2(CO)12(MU-BR)] and [N(PPH3)2][IR6(MU-CO)2(CO)12(MU-X)] (X=I OR SCN)

The salts of the monosubstituted hexanuclear anions [Ir6(CO)14X]- [X = Cl (1,)Br (2), I (3), or SCN (4)] have been prepared by treating [Ir6(CO)16] with halides or pseudohalides at room temperature in tetrahydrofuran solution. The three anions consist of slightly distorted octahedra of iridium atoms bearing twelve terminal and two edge bridging carbon monoxide groups. In all cases the halogen atoms or the pseudohalogen group adopt a bridging co-ordination on an Ir-lr edge.